Is this the right Q45 diff setup (pic)

[Kingtal0n]

Hello friends,

I am trying to find a early 90-94 Q45 differential, 3.54:1 ratio

I think I found one. But its very hard for me to know exactly.
For example I see some Hicas stuff in the back. And I am not sure about the flanges and axles etc... or the driveshaft length. Does traction control or ABS matter? I really dont want to re-size my driveshaft.

[aack]

Well I can't tell you if the output shafts will fit your car because I don't know your car. I'm almost positive that S13's came with 6 bolt output shafts while S14's had 5. Because of all the mixing and matching that can happen with R200V, I would check your car. That Q45 in that picture has 5. The output shafts can always be changed to the other type but just note, there is a difference between open and lsd shafts.

Every Q45 or J30 you try to get a diff from will have ABS. They will all have that extra 1/4in or whatever it is that will push your driveshaft forward. Most people run it with no problems, but I didn't because I didn't want to resize and didn't want to deal with diff bushings. It's possible to swap Q45 internals into open diff pumpkin but after the headache I went through, I wouldn't recommend it. So up to you.

Another tip, spin the wheels and make sure they both spin forward with little to no play. I've found J30 vlsds in the junkyard that were flogged out and acted like open diffs even though they were genuine lsds from the factory.

Here is everything you need to know about years and what to get: http://ka24development.com/vlsd.html

[Kingtal0n]

I know you are just trying to help, but you didn't answer the question.
All I asked is: Is that a Q45 1994 3.5:1 differential in the picture. y/n


further,
that link you provided has misinformation in it. I don't want to re-read right now but I am sure there is bad notes.


also, your information cannot be accurate either, because I have right now in my possesion a J30 differential with no additional 1/4" of input snout length, it exactly mirrors the OEM differential with respect to driveshaft length. So not all J30 and Q45 have that extra 1/4". I just don't know which ones do and which do not. Soon I will measure 3.5:1 ratio Q45 6-bolt differential from 94' and compare.

[aack]

Originally Posted by Kingtal0n

I know you are just trying to help, but you didn't answer the question.
All I asked is: Is that a Q45 1994 3.5:1 differential in the picture. y/n


further,
that link you provided has misinformation in it. I don't want to re-read right now but I am sure there is bad notes.


also, your information cannot be accurate either, because I have right now in my possesion a J30 differential with no additional 1/4" of input snout length, it exactly mirrors the OEM differential with respect to driveshaft length. So not all J30 and Q45 have that extra 1/4". I just don't know which ones do and which do not. Soon I will measure 3.5:1 ratio Q45 6-bolt differential from 94' and compare.

Welp I don't see any evidence, but I guess I can't help you because you know much more than me. All I know is I've dealt with over 6 j30/q45 lsds for me and mostly helping friends. I've just followed that link and its been spot on for me, every one I've worked on has had that extra abs sensor so idk. Does your diff that doesn't have the sensor have rubber bushings?

I wouldn't know about the ratio because I've always used the stock open ring and pinion.

[Kingtal0n]

I started out with an OEM 96 nissan 240sx differential

I put in a 5-bolt axle Q45 differential from 97 3.7:1 ratio and it was the same driveshaft length.

then I put in a 5-bolt axle J30 differential 3.9:1 ratio and it was the same driveshaft length.

I dont recall any sensors on any of them.

Now I am putting in a 3.5:1 ratio (hopefully) Q45 1994 differential. Could we possibly be looking at a situation where if there is no sensor then it will be the same length as the other 3 I had? Its from 94 so I am thinking ABS was in an infancy back then. Hopefully it just fits... but yeah right.

I guess some come without ? I read this on a random car part site:
"1991 – 1996 Infiniti Q45 with traction control. (Ones without traction control have ABS sensor on nose making nose ½” longer.)"

So WITHOUT traction control has ABS? That doesn't make sense.

Found this picture.


Sigh. Whats another day to cut a driveshaft anyways. I waited over a year already I can wait one more day I guess. Itch itch , I itch all over need to drive this thing

[aack]

You could be right, no one perfectly knows all the exact things Nissan was doing 25 years ago. They could have offered some without abs, but my thinking was that all q45/j30s have vlsds, so I assumed they all came with the same one making them all have abs standard. But who knows?

I didn't want to chop my driveshaft and also wanted to keep my speedo as correct as possible, so I just used the vlsd with stock ring and pinion, but good luck trying to find what you want. No matter what you use it will always fit, it just depends if pushing your driveshaft will kill your inner ocd. Unfortunately, most kids that drive these cars don't give a f**k.

[Kingtal0n]

Me: "Hi I'd like to buy a Q45 diff, the driver side axle, and both hubs"
Scrapyard: "Sure thing, just the driver side axle? and you don't need spindles?"
Me: "that is correct you can keep the the spindles and all that, unless its too much trouble to separate them"
Scrapyard: "Oh its no problem to separate the hubs etc... "

One week later I go to pick up the diff, axle, and hubs from the shipping company.
I open my trunk expecting a guy to roll around the corner with a pallet, and some stuff strapped to that pallet. That I was going to unstrap and put into my trunk.

Well, he rolls around the building with a forklift and a pallet containing this:





LOL At this this arriving and me not being able to fit it in the corolla I was driving. And I don't carry a 34mm socket or whatever with an impact either to remove the axle nut.

It started raining. And it rained the next 3 hours.

I drove it back with the door open on one side
it leaked gear oil and power steering fluid (which looked red so... guess what it was) and smeared grease everywhere and broke both door panels and tore the head liner. But I got it back now ready to clean it up and get it in. Looks like no ABS sensor again so score, shouldn't need to cut the driveshaft. I am using a 4l80e yolk with a 4l60e length driveshaft so there is only 1/4" or so of ... whatever its called



The VLSD action feels tight, right like every vlsd I ever felt.
However one of the output flanges has a little bit of free play. I can slop it in and out a little bit. The other one doesn't do that. Is something bad, some kind of thrust spacer?

[Kingtal0n]

found this
https://www.zcar.com/forum/12-90-96-...free-play.html

Mine does the same thing as his on the same side!

score one for its normal: 1

its broken: 0

I'm going to re-drill the input flange and I think thats all I need to do!

[Kingtal0n]

To get the hub out I had to remove the Brake DRUM and E-brake related stuff. Also there was this 1 and 1/16" nut on a flange of the hub holding the brake drum in.

I am guessing I dont need any of that stuff. I took off the brake dust shields, rotors, drum hardware, and removed the hubs alone by itself.

pretty amazing how old this stuff is and still feels like its good inside.

[Rb26kouki]

You can also get a 95-01 q45 diff with 3.91 ratios and swap the output shafts from a 90-94
That’s what I did

[Kingtal0n]

Have a 3.9 in there right now



too much gearing for an automatic overdrive 4-speed behind a V8


15-18mpg sometimes 13. I can touch 22mpg highway if I drive perfect.

With the 3.5 I will gain 2-3mpg everywhere and should be able to top 25+ with some other things I will be doing as well. looking for 27 or 28 final
plus now I will be able to go over 130mph in 3rd gear without overrevving the engine at the trap

Edit: Also just for clarification the 3.9 Ratio I guess is found in J30 differentials. The Q45 has a 3.5 or 3.7:1, whereas J30 is 3.9
So the diff in my car is a 3.9 5-bolt axles with OEM 240sx splines, J30 axles J30 differential.
Couple weeks ago I had a Q45 3.7:1 ratio unit in my car with the same axles. 5-bolt, stock hub splines, fit that one also.

I guess you are saying you needed the big 32 spline axle stuff in the newer 3.7 Q45 differential so you swapped output shafts.
My biggest fear is pulling apart one of these differentials to do anything inside them. I've read that you need some kinda special "rolling torque" measurement and who knows what other crush sleeve or weird backlash stuff. I am not setup for that kinda stuff and I don't have any of the special tools so it was imperitive to use a drop-in OEM unit that I didn't need to remove or change anything to make it work. If it wasn't for this differential existing, I probably would have went 6-speed manual instead of automatic, that is how important it was for me to know I could get a 3.5:1 in the back of the car using a .75:1 overdrive to achieve reasonable economy.

these ancient Q45 with 3.5:1 ratio use the stupid huge 32 spline stuff, 6-bolt like Z32. It had drum E-brake on top of disc caliper brakes in the rear. *shudders*

[Kingtal0n]

Drill some holes,



Quick shot of my exhaust for fun


Inspect the ring gear a little



Diff is in!
... I am rich everywhere now in my fuel map. Cruising at 65mph I am seeing 13.8's instead of usual 15's
So now a retune and some MPG calculations... should have some accurate new MPG data shortly. check build thread if curious, not sure I will bump this one again unless theres questions, problem, or new pics maybe of it installed